Gaya APA

Friederich,M,C., . (1989). Feasibility Study Petangis Coal Deposit Block 5 Kalimantan : Section 2 Resource Report . : P.T. Utah Indonesia.

Gaya MLA

Friederich,M,C., . "Feasibility Study Petangis Coal Deposit Block 5 Kalimantan : Section 2 Resource Report". : P.T. Utah Indonesia, 1989. Text.